Code 51, EGR System & EGR Temp Sensor (EGRTS) CKT, Temp Too Low Or Too High (CALIF. Only): Notes

This code indicates EGRTS has signaled ECM of an EGR temperature greater than, or less than, the calibrated range. Code 51 will set when the following conditions are met: Shorted Sensor

• Engine coolant temperature is less than 104°F (40°C).
• Exhaust gas temperature is greater than 428°F (220°C).
• Conditions present for 3 seconds.

Open Sensor or EGR Valve Passage Plugged

• Engine coolant temperature is greater than 158°F (70°C).
• Intake air temperature is greater than 122°F (50°C).
• Conditions present for 80 seconds.
  NOTE: Test numbers refer to test numbers on diagnostic chart.

1. Checks for proper EGR valve operation.
2. Checks for 5-volt reference signal to EGR temperature sensor.
3. Checks for a short to voltage in Red/Green wire.
4. Checks for an open Gray/Yellow wire, faulty ECM or a faulty EGR temperature sensor.